President Obama and British Prime Minister David Cameron meet in the Oval Office of the White House in Washington, DC, May 13, 2013. / JIM WATSON AFP/Getty Images

by Aamer Madhani, USA TODAY

by Aamer Madhani, USA TODAY

WASHINGTON -- Facing a wall of outrage from GOP lawmakers over revelations that the Internal Revenue Service targeted "tea party" groups and non-profit organizations that criticized the government, President Obama on Monday called the actions by agency personnel "outrageous" and said "there is no place for it."

The president, who appeared alongside British Prime Minister David Cameron at the White House, weighed in on the IRS controversy for the first time and attempted to head off snowballing criticism from Republican lawmakers that he hadn't personally condemned the agency's targeting of conservative political groups for extra scrutiny.

Obama said he first learned about the IRS actions from news reports Friday. He said those responsible for the practice should be held "fully accountable." White House spokesman Jay Carney said later on Monday that White House Counsel's Office was alerted during the week of April 22nd that the agency's inspector general was completing a review about matters involving the office in Cincinnati.

Lois Lerner, the IRS director of exempt organizations, on Friday admitted the agency made "mistakes" in the last few years and that employees in the agency's Cincinnati office routinely required conservative organizations seeking non-profit status to undergo more scrutiny.

Multiple conservative groups have said their applications were delayed and returned with lengthy requests for supporting materials, sometimes including website printouts and lists of guest speakers.

"You don't want the IRS ever being perceived to be biased," Obama said.

Even as Obama attempted to make clear his unhappiness with the IRS, Republicans continued to level their criticism against the agency and the administration.

"It is clear the IRS cannot operate with even a shred of the American people's confidence under the current leadership," Rubio wrote in a letter to Treasury Secretary Jack Lew. "Therefore, I strongly urge that you and President Obama demand the IRS commissioner's resignation, effectively immediately. No government agency that has behaved in such a manner can possibly instill any faith and respect from the American public."

Some Democrats, including Sen. Max Baucus, on Monday joined Republican calls for a Congressional investigation of the IRS.

"I want to review the inspector general's report first, but the IRS should be prepared for a full investigation into this matter by the Senate Finance Committee," said Baucus, of Montana, who is chairman of the committee. "The IRS will now be the ones put under additional scrutiny."

Obama added that neither party wants the IRS to be perceived as "anything less than neutral in terms of how they operate." He added: "This is something that I think people are properly concerned about."

Still, the president pointed to the inspector general's ongoing investigation, saying he would not comment prematurely on specific findings.

The president added that his administration will get to the bottom of what happened at the IRS. "I have no patience for it. I will not tolerate it. "

Obama also faced a difficult question about the administration's response to last year's terror attack on a U.S. diplomatic post in Benghazi, Libya, that left four Americans dead, including Ambassador Christopher Stevens.

E-mails unveiled last week show the State Department and other senior administration officials asking that references to terror groups and prior warnings be deleted from a unclassified memo on talking points about the incident shortly after the Sept. 11 attack.

GOP lawmakers have also criticized the State Department board that reviewed the incident for not interviewing then-Secretary of State Hillary Rodham Clinton.

As the president held his press conference, House Oversight and Government Reform Committee Chairman Darrell Issa announced that he had sent letters to Benghazi Accountability Review Board (ARB) co-chairs, former ambassador Thomas Pickering and former admiral Mike Mullen, requesting that they submit to transcribed interviews in anticipation of a public hearing on the board's investigation.

"Three senior State Department officials who testified at the hearing criticized the ARB's work as 'incomplete' and flawed because the ARB did not interview key witnesses and failed to hold senior officials accountable," wrote Issa in the letter to Pickering. "On May 12, 2013, you defended the ARB's work on Face the Nation. You stated that those criticisms are 'unfair.' â?¦ The White House and the State Department have touted the ARB's report as the definitive account of how and why the Benghazi attacks occurred. It is necessary for the committee to understand whether the criticisms of the ARB's work that we heard from witnesses on May 8, 2013, are valid."

But the president pushed back, saying his administration officials have been forthcoming about Benghazi and suggesting that Republicans are more interested in scoring political points than figuring out how to prevent such incidents from happening again in hot spots where U.S. diplomats and other personnel are deployed.

"There is no there, there," Obama said.

Obama and Cameron met for about hour at the White House before the news conference. Cameron said their talks centered on the economy, the ongoing civil war in Syria and next month's Group of Eight summit that Cameron will host in Northern Ireland.

Both Cameron and Obama acknowledged they have a difficult task in persuading Russia to abandon Syrian President Bashar Assad's regime.

Obama noted that there are long-term "suspicions" by Russia toward the G-8 alliance - which includes the USA, Britain and Russia -- but both he and Cameron were trying to "break down" some of those suspicions.

"As a leader on the world stage, Russia has an interest and obligation to resolve this issue that can lead to an outcome we all want to see in the long-term," Obama said.

"Syria's history is being written in the blood of her people," Cameron said. He added, "and it is happening under our watch."